In known fuel rails for injector-based fuel injection systems, a pressure pulsation damper is believed to be used in fuel rail assemblies. Insertion of the pressure pulsation damper into the fuel rail assembly is typically accomplished by placing the pressure pulsation damper through an open end of the fuel rail. The open end of the fuel rail is believed to be sealed in order to prevent fuel leakage from the fuel rail i.e., a hermetic seal. The open end of the fuel rail is believed to be sealed by conventional soldering, induction welding, resistance welding, or the more well-established use of crimping an assembly that utilizes an O-ring joint. The O-ring joint use is believed to be prone to excessive evaporative emissions. The other techniques are believed to require excessive heat or electricity in order to seal the fuel rail. The excessive heat generated by some of these techniques may damage the pressure pulsation damper thereby rendering the internal damper unsuitable in damping pressure pulsations.
A known pressure plug assembly uses a cup-shaped sealing cap with a bellow damper attached to reduce pressure fluctuations in the fuel rail. The sealing cap compresses an O-ring joint against a connecting sleeve and is crimped to the connecting sleeve at its radial flange. As previously mentioned, this configuration is prone to excessive evaporative emissions that reduce its effectiveness.
Another known pressure plug assembly uses a deformable cylindrical sleeve member which is placed into a tube end. The sleeve's peripheral shoulder abuts against the tube end to position an interior tapered portion of the sleeve. Adjacent the open-end, at the desired location of the seal to be formed within the tube, a hard plug member having a tapered portion, is pressed into the tapered portion of the sleeve to deform the sleeve and form the tube seal in the zone of the tapered surfaces. Neither the deformable cylindrical sleeve nor the hard plug member shows any outward or inward projections that are pressed against each other to seal the tube
Still another known plug assembly for pressurized piping utilizes a bore plug that fits into an enlarged end of a heat exchanger tube. The bore plug is believed to have a sealing member that fits into the heat exchanger tube and a holding member that interlocks with the sealing member. The sealing member is tapered and includes three circumferential indentations along its longitudinal axis that interlock with the circumferential projection of the holding member. The holding member is manually pressed into the sealing member and locks into place at one of the three indentation positions.